The contents in this section only provide background information relating to the present invention which does not necessarily constitute the prior art.
A joint adopting thread to achieve connection is widely used in the engineering due to the convenient installation thereof. This joint having thread (also referred to as thread joint hereinafter) is usually used to sustain an axial load. When a radial load or torque is applied on this thread joint, the thread on the joint is apt to be damaged which will lead to failure of the whole thread joint.
Especially in the field of the aircraft, the thread joint is frequently used to connect two control airfoils which need synchronous movement. For example, when the control airfoil is a spoiler, the spoiler will apply the radial load to the thread joint during the movement and thus it will decrease the reliability of the thread joint and even break the thread joint. On the other hand, when two spoilers are to be connected with each other by the thread joint, the thread joint can usually installed from one side which decreases the assemblability of the thread joint. Moreover, for such application area as aircraft which requires high safety and assembly accuracy, the thread joint still need improvement.